I have intended a unique winch for use in safely lowering a person from an elevated position such as the window of a high rise building when a fire or other emergency prevents use of elevators and other usual exits.
As the result of a fire or other emergency, the elevators and stairwells of a high rise building may be unusable. In the past a number of devices have been suggested for lowering persons trapped in the upper floors of a burning high rise building to the ground. See, for example, U.S. Pat. Nos. 1,203,467; 3,850,263; 3,861,496; 4,253,643; 4,287,963; and 4,327,818.
However, as can be seen from the foregoing patents, the state of the art does not include a small, self-contained device which can be carried into the building by one person such as an overnight hotel guest, a device whose working parts are protected by a casing, and a device providing two independent safety mechanisms to assure that the person being lowered to the ground is lowered at a safe, automatically controlled rate of descent.
My invention provides a compact, relatively inexpensive and portable winch which can be affixed to a hook or other secure fitting at or near the window opening to provide for the prompt descent of one or more persons from the upper floor of a high rise building.
The winch which I have invented includes two separate but cooperating mechanisms to guarantee that the person being lowered to safety will descend at a safe and controlled rate. In the preferred form of my invention, these cooperating mechanisms are a cam operated disc brake and a gear driven centrifugally operated clutch.
Briefly stated, my unique winch comprises:
a drum-shaped cylindrical casing;
a rotatable shaft within the casing mounted on a pair of bearings located on opposite sides of the casing;
a spool axially affixed to the shaft;
a cam plate affixed to the shaft;
a brake disc affixed to the shaft;
a first gear affixed to the shaft;
an air pump mounted on the casing and having a piston rod accuated by the rotation of the cam plate;
a disc brake assembly activated by the air pump;
a cable wound upon the spool;
a centrifugally operated clutch mechanism mounted on the casing and including a second gear meshed with the first gear; and
means including a crank attached exteriorly of the casing to one end of the shaft for rewinding the cable onto the spool.